Previously, compounds having the following Formula (a) have been disclosed in documents below.

Patent Document 1 discloses compounds, for example, shown below, which are demonstrated to be valuable as antiviral agents.

Patent Document 2 discloses compounds, for example, shown below, which are demonstrated to be valuable as therapeutic agents for Alzheimer's disease.
 Substitution position of ExampleL1double bond 14-fluorophenylE   2+4-fluorophenylZ 32,4-difluorophenylE 42,4-difluorophenylZ 53-chlorophenylE 63-chlorophenylZ 72-chlorophenylE 82-chlorophenylZ 94-methoxyphenylE104-methoxyphenylZ
Patent Document 3 discloses compounds, for example, shown below and describes a method for synthesizing Rev-suppressing compounds and a method of screening the same.
 ABC2,4-dichlorophenylphenylcyclohexyl2-naphthylα,α,α-trifluoro-m-toluyl1,2,3,4-tetrahydronaphth-1-yl2-naphthylα,α,α-trifluoro-m-toluyldiphenylmethyl2,4-dichlorophenylα,α,α-trifluoro-m-toluyldiphenylmethyl2-naphthylα,α,α-trifluoro-m-toluyl2-(p-toluyl)ethyl2-naphthylα,α,α-trifluoro-p-toluyldiphenylmethylp-toluyl2,4-difluorophenyl2-hydroxyphenethyl2-naphthyl3-quinolinyl(1-naphthyl)methyl2-naphthylα,α,α-trifluoro-p-toluyl4-phenylbuto-2-yl2,4-dichlorophenyl4-biphenylyldiphenylmethyl
Patent Document 4 discloses compounds, for example, shown below, which are demonstrated to be valuable as antihypertensives.

However, none of the above-mentioned Patent Documents 1 to 4 mentions activity for bone metabolic diseases and inflammation, and therefore the purposes of the uses of such compounds are quite different from those of the present invention. Furthermore, only the structures have been known for the compounds shown below, and the uses thereof are not known at all.

In general, in normal bone metabolism, bone resorption by osteoclasts is balanced with bone formation by osteoblasts to maintain homeostasis. It is thought that bone metabolic diseases are caused when the balance between the bone resorption and the bone formation is deteriorated. Bones retain about 99% of the total calcium in a living body and play an important role for maintaining a constant blood calcium concentration by bone formation and bone resorption. If the osteoclasts which are mainly responsible for bone resorption are abnormally formed or activated, bone resorption is accelerated to increase the blood calcium concentration, and thereby bone metabolic diseases, such as hypercalcemia, are caused.
It is known that bone metastasis of cancer causes abnormal secretion of cytokines resulting in development of hypercalcemia. In this process, bone resorption by osteoclasts is accelerated, so that the blood calcium concentration is increased (Non-Patent Document 1). Prognosis of cancer patients accompanied by cancerous hypercalcemia is generally poor.
Moreover, in rheumatoid arthritis, osteoarthritis and the like, abnormal formation or activation of osteoclasts is known as one of main causes of various symptoms in bones and joints (Non-Patent Document 2). Patients with rheumatoid arthritis, osteoarthritis, and the like suffer from severe pain, which brings considerable disadvantages to the lives of the patients.
Furthermore, when the balance between bone resorption and bone formation continuously inclines toward the bone resorption due to a decrease in secretion of female hormones after menopause or due to ageing, bone density is lowered and osteoporosis is developed. Also in this case, osteoclasts are also responsible for the bone resorption.
When aged patients with a high risk of osteoporosis suffer fractures, a possibility of becoming bedridden is high, which is a social problem (Non-Patent Document 3).
Conventionally, for these states of diseases, hormone replacement therapy using estrogen or the like has been conducted or a therapeutic agent such as a bisphosphonate or a calcitonin for suppressing the activity of osteoclasts has been administered (Non-Patent Document 4). However, none of these existing agents are satisfactory agents for essentially treating hypercalcemia or bone metabolic diseases, and thereby the development of agents having high therapeutic efficacy is desired.
[Patent Document 1]
    International Publication No. WO2004/002977[Patent Document 2]    International Publication No. WO00/24392[Patent Document 3]    Japanese Publication of International Patent Application No. 2001-506965[Patent Document 4]    British Patent No. 1,113,569[Non-Patent Document 1]    Jean-Jacques Body, CANCER Supplement, vol. 88, p. 3054 (2000)[Non-Patent Document 2]    E. Romas, et al., Bone, vol. 30, p. 340 (2002)[Non-Patent Document 3]    Bruno Fautrel, et al., Current Opinion in Rheumatology, vol. 14, p. 121 (2002)[Non-Patent Document 4]    Mohammad M. Iqbal, et al., Missouri Medicine, vol. 99, p. 19 (2002)